In order to improve office environments and the like, many electrographic image forming apparatuses employ charging methods for charging a photosensitive drum (photosensitive member) through which ozone is generated a little in recent years. A charging method using a DC charging roller has been known as one of the charging methods in which ozone is generated a little. However, an image forming apparatus employing the charging method using the DC charging roller can charge the photosensitive drum less than an image forming apparatus employing a typical charging method (scorotron method). For this reason, electric charge charged to the surface of the photosensitive drum by a transfer electric filed may not be canceled through charging in subsequent processing in the image forming apparatus employing the charging method using the DC charging roller. As a result, the surface potential of the photosensitive drum may be non-uniform so that an electrostatic latent image subjected to transfer in the previous processing may remain on the surface of the photosensitive drum. In a situation as above, generally-called transfer memory, which is a phenomenon in which image density differs in a halftone image or the like, may be likely to occur. An invention that solves the above problem is disclosed in Patent Literature 1.
Patent Literature 1 discloses a tandem image forming apparatus that removes charge from a positively chargeable photosensitive drum before transfer. Specifically, the image forming apparatus disclosed in Patent Literature 1 includes a plurality of image forming units for respective colors disposed along a circulation direction (movement direction) of an intermediate transfer belt. The image forming units each include a static eliminator that irradiates with light a photosensitive drum located adjacently upstream in the circulation direction of the intermediate transfer belt. Further, a static eliminator among the static eliminators included in the respective image forming units that is located between adjacent photosensitive drums irradiates with light also a photosensitive drum adjacently downstream in the circulation direction of the intermediate transfer belt. In the above configuration, the surfaces of the respective photosensitive drums that each carry a toner image (the surfaces of the photosensitive drums before toner images are transferred) are subjected to static elimination, thereby preventing occurrence of transfer memory.